Brushes have been used for many years to polish, clean, and abrade a wide variety of substrates. These brush products typically have a plurality of bristles that contact the substrate. Abrasive particles can be added to bristles to increase their abrasiveness. There are many manufacturing steps necessary to manufacture a conventional abrasive brush having bristles which contain abrasive particles. A mixture of abrasive particles and a thermoplastic binder may be combined and then extruded to form a bristle. The bristle is then cut to the desired length. A plurality of these bristles are then mechanically combined to form a brush segment. Next, a plurality of these brush segments may be installed on a hub or plate to form a brush.
One example of such a brush is disclosed in U.S. Pat. No. 5,045,091, "Method of Making Rotary Brush With Removable Brush Elements" (Abrahamson et al.). In Abrahamson et al., a plurality of abrasive bristles are mechanically clamped together and a root system is installed to form a brush segment. A plurality of these brush segments is installed on a rotary hub to provide a radial brush. Another arrangement for mechanically mounting bristles on a hub to form a radial brush segment is disclosed in U.S. Pat. No. 5,233,719, "Apparatus and Brush Segment Arrangement for Finishing Wheel Brushes" (Young et al.). Young et al. teach a brush segment comprising a substrate with a carpet of bristles mounted on one side of the substrate, by means of a polymeric resin for example, and a root system extending from the opposite side of the substrate. The individual brush segments are adapted for mounting in longitudinal slots in a cylindrical hub. U.S. Pat. No. 5,400,458 (Rambosek) teaches a brush segment having a plurality of bristles embedded in a polymeric base portion. A root means for attaching the segment to a hub can be integrally molded with the base.
Co-pending U.S. patent application Ser. No. 08/431,910 (Johnson et al.) , issued as U.S. Pat No. 5,679,067. discloses an integrally molded abrasive brush for rotary tools, comprising a generally planar flexible base having a first side and a second side, and a plurality of bristles extending from the first side of the base. The bristles have an aspect ratio of at least 2 and are integrally molded with the base. The molded abrasive brush comprises a moldable polymeric material which includes abrasive particles interspersed throughout at least the bristles. The bristles extend generally perpendicular to the base, parallel to the axis of rotation of the molded abrasive brush. In a preferred embodiment, the bristles contact the workpiece at the juncture of the leading edge of the tip of the bristle and the outermost portion of the side surface of the bristle.
U.S. Pat. No. 5,427,595 (Pihl et al.) discloses an extruded abrasive filament including a first elongate filament component having a continuous surface throughout its length and including a first hardened organic polymeric and a second elongate filament component coterminous with the first elongate filament component, including a second hardened organic polymeric material in melt fusion adherent contact with the first elongate filament component along the continuous surface. The second hardened organic polymeric material can be the same or different than the first hardened organic polymeric material. At least one of the first and second hardened organic polymeric materials includes a thermoplastic elastomer having abrasive particles adhered therein. Also disclosed is an abrasive article comprised of at least one abrasive filament mounted to a substrate such as a hub adapted to be rotated at a high rate of revolution.
U.S. Pat. No. 5,460,883 (Barber et al.) discloses a composite abrasive filament which includes at least one preformed core at least partially coated with a thermoplastic elastomer having abrasive particles dispersed and adhered therein, the thermoplastic elastomer and abrasive particles together comprising a hardened composition. The composite abrasive filament has a hardened composition over at least a portion, preferably over the entire surface of at least one preformed core. The preformed core is formed in a step separate from and prior to one or more coating steps, one of which coats the preformed core with abrasive-filled thermoplastic elastomer.
U.S. Pat. No. 3,618,154, "Brush," Muhler et al.), discloses brushes, and more particularly an integrally molded, one-piece brush, especially a toothbrush, in which the plastic material from which the brush is molded incorporates up to about 30% by weight of an abrasive material, especially a dental abrasive material. Muhler states that, depending upon the individual use to which the brush may be put, the abrasive component thereof may be omitted. Without providing any details as to the configuration of such an embodiment, Muhler states that a relatively thin elongated brush head with bristles formed thereon could be attached to a wheel and thereby serve as a buffing brush.
U.S. Pat. No. 3,233,272, "Rotary Brush," (Pambello), discloses brushes, particularly rotary brushes of the annularly or spirally arranged brush strip type which are primarily adapted for heavy duty such as brushing paved streets, sidewalks, concrete flooring and the like. In one embodiment, the rotary brush of Pambello comprises a cylindrical rotatable structure, a brushing element formed of a unitary strip of yieldable plastic material spirally arranged on the drum, the strip having a lengthwise extending base and having vane means extending outwardly from the base and formed with a tip at the outer end thereof. Alternatively, there may be a number individual strips circularly arranged on the drum. The brush strip of Pambello may be formed of plastic materials by molding or extruding and cutting operations.
It is seen that there is a need to provide a radial abrasive brush segment, and a brush comprising the brush segments, that is easily and inexpensively manufactured, and which provides suitable durability and abrading characteristics.